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111.
Kaori Sakurai 《Tetrahedron letters》2010,51(29):3724-3727
Oligosaccharides represent potentially useful scaffolds for the development of peptidomimetics. We report here the design and synthesis of functionalized trisaccharides modeled after an α-helical 15-mer peptide region of p53 which binds to its cellular regulator MDM2. The trisaccharide scaffold was obtained efficiently by applying the sulfoxide glycosylation reaction as a key methodology. 相似文献
112.
Structural effects of electrochemical oxidation of formic acid on single crystal electrodes of palladium 总被引:1,自引:0,他引:1
Hoshi N Kida K Nakamura M Nakada M Osada K 《The journal of physical chemistry. B》2006,110(25):12480-12484
Structural effects on the rates of formic acid oxidation have been studied on Pd(111), Pd(100), Pd(110), and Pd(S)-[n(100) x (111)] (n = 2-9) electrodes in 0.1 M HClO4 containing 0.1 M formic acid with use of voltammetry. On the low index planes of Pd, the maximum current density of formic acid oxidation (jP) increases in the positive scan as follows: Pd(110) < Pd(111) < Pd(100). This order differs from that on the low index planes of Pt: Pt(111) < Pt(100) < Pt(110). Pd(S)-[n(100) x (111)] electrodes with terrace atomic rows n > or = 3 have almost the same jP as Pd(100), except Pd(911) n = 5. The value of jP on Pd(911) n = 5 is 20% higher than those of the other surfaces. Pd(311) n = 2, of which the first layer is composed of only step atoms, has the lowest jP in the Pd(S)-[n(100) x (111)] series. The adsorption geometry of the reaction intermediate (formate ion) is optimized by using density functional theory. 相似文献
113.
114.
Inkjet-printed paperfluidic immuno-chemical sensing device 总被引:1,自引:0,他引:1
Koji Abe Kaori Kotera Koji Suzuki Daniel Citterio 《Analytical and bioanalytical chemistry》2010,398(2):885-893
This paper reports on an inkjet printing method for the fabrication of lateral flow immunochromatographic devices made from
a single piece of filter paper by patterning microfluidic channels and dispensing immunosensing inks, requiring only a single
printing apparatus. This “paperfluidic” immunosensing device allows for a less time-consuming and more low-cost fabrication
compared with the conventional immunochromatographic strips requiring multiple pads, plastic or nylon backing, and a plastic
case. A sandwich immunoreaction was performed on the patterned immunosensing paper device, and the sensitivity of the device
was optimized with an IgG model analyte. Inkjet-printed antibodies on the test line and the control line were immobilized
by physical adsorption, resulting in a very simple fabrication method applicable for pure cellulose surfaces. The color intensity
in the test line and the control line was determined both by naked eye and by means of a color scanner in combination with
a simple computer program. With the resulting paperfluidic immunosensing device, human IgG concentrations at least down to
10 μg/l could be detected within 20 min. Additionally, in order to demonstrate the feasibility of a total multianalyte sensing
system, a combined immuno-chemical sensing device was also fabricated by patterning an additional microfluidic channel for
a chemical assay onto the same paper substrate. This low-cost multianalyte paperfluidic sensing device thus demonstrates the
feasibility of simple, portable, and disposable tools for pathogen detection in the field of medical, environmental, and food
analyses, possibly resulting in useful devices in remote settings and less-industrialized countries. 相似文献
115.
Tubiferal A, a novel rearranged triterpenoid lactone, has been isolated from field-collected fruit bodies of the myxomycete, Tubifera dimorphotheca, and its structure elucidated by spectral data. Tubiferal A (1) possesses a 9,10-secocycloartan-16,21-olide skeleton, and this new compound exhibited a reversal effect of vincristine (VCR) resistance (more than 4-fold) against VCR-resistant KB cell lines. Tubiferal B (2), corresponding to the seco acid of 1 was also isolated, but showed no comparable activity. 相似文献
116.
This paper presents data on adsorption of immunogamma globulin (IgG) onto synthetic rodlike calcium hydroxyapatite particles (CaHaps) with various particle lengths and calcium/phosphate (Ca/P) atomic ratios ranging from 1.54 to 1.65 and compares the obtained results to those of acidic (bovine serum albumin, BSA), neutral (myoglobin, MGB), and basic (lysozyme, LSZ) proteins reported before. The effect of electrolyte concentration on IgG adsorption was also examined. The initial rate of IgG adsorption was similar to that of BSA and was slower than that of MGB and LSZ. This fact was interpreted by the difference in the structural stability and molecular weight of these proteins. The isotherms of IgG adsorption onto the CaHap particles were of pseudo-Langmuir type. The saturated amount of adsorbed IgG values (nsIgG) for the particles with mean particle length less than 70 nm decreased with increasing Ca/P ratio. The adsorption behavior of IgG molecules was very similar to that of basic LSZ, though IgG has zero net charge. The nsIgG value was increased with increased mean particle length of CaHaps; the relationship was less significant than that for BSA but similar to those for MGB and LSZ. The similar adsorption behavior of IgG and LSZ suggested that the Fab parts of IgG molecules preferentially adsorb onto CaHap to provide the reversed Y-shaped conformation of IgG. The change of the adsorption mode of IgG molecules from the reversed Y-shaped conformation to side-on by "spreading" the Fc part of IgG molecules onto the particle surface over a longer adsorption time was suggested. The nsIgG value was increased with increasing electrolyte concentration by screening the intra- and intermolecular electrostatic interactions of proteins. 相似文献
117.
A restricted access media-molecularly imprinted polymer was prepared using bisphenol A (BPA)-d16 as a template molecule, and was successfully applied to direct injection analysis of BPA in serum combined with column-switching LC-MS. 相似文献
118.
5,5-Dicyano- and 5-cyano-5-ethoxycarbonyl-5,6-dihydro-3,7-diphenyl-4H-1,2-diazepines were prepared by the condensation of α-bromoacetophenone azine with malononitrile and ethyl cyanoacetate in the presence of sodium ethoxide, respectively. Halogenations of the dihydrodiazepines gave pyridazines, diazanorcaradienes, 4,4,6,6-tetrachlorodihydrodiazepines, and/or a 4-chloropyrazole whose relative yields strongly depended upon the nature of 5-substituents of the dihydrodiazepines as well as the reaction conditions. 相似文献
119.
Yamaguchi H Tsubouchi K Kawaguchi K Horita E Harada A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(23):6179-6186
Peroxidase activity of a complex of water-soluble cationic metalloporphyrin with anti-cationic porphyrin antibody is reported. Antibody 12E11G, which was prepared by immunization with a conjugate of 5-(4-carboxyphenyl)-10,15,20-tris(4-methylpyridyl)porphine iodide (3MPy1C), bound to tetramethylpyridylporphyrin iron complex (FeIII-TMPyP) with the dissociation constant of 2.6 x 10(-7) M. The complex of antibody 12E11G with FeIII-TMPyP catalyzed oxidation of pyrogallol, catechol, and guaiacol. A Lineweaver-Burk plot for the oxidation of pyrogallol catalyzed by the FeIII-TMPyP-antibody complex showed Km=8.6 mM and kcat=680 min(-1). Under the same conditions, Km and kcat for horseradish peroxidase (HRP) were 0.8 mM and 1750 min(-1), respectively. Although the binding interaction of the antibody to the substrates was one order lower than that of native HRP, the peroxidase activity of this system was in the same order of magnitude as that of HRP. 相似文献
120.
Zeng H Schelly ZA Ueno-Noto K Marynick DS 《The journal of physical chemistry. A》2005,109(8):1616-1620
The structures of (PbS)n (n = 1-9) clusters are investigated with density functional theory at the B3LYP level. Various pseudopotential basis sets on lead and the 6-31+G basis set on sulfur were employed. Full geometry optimization and extensive searches of the potential energy surface were carried out for clusters with n = 1-6. We find that even small PbS clusters (n > 2) start to take on the characteristic features of the rock salt structure of solid-state PbS (galena). The origin of some of the structural aspects of these crystals is shown to be associated with the partial covalent nature of the Pb-S bond. The magnitude of the HOMO-LUMO gap oscillates with increasing size of the clusters, in agreement with the observed behavior of the corresponding UV absorption bands of ultrasmall PbS quantum dots. Direct conformation of this oscillation was found by CIS(D) calculations, for which the absorption with the largest oscillator strength oscillates as the clusters grow from PbS to (PbS)9. 相似文献